Interpretive Summary: Various tillage tools leave widely varying amounts of crop residue on the soil surface depending upon their methods of disrupting and moving soil. Implements are also affected to varying degrees by operational parameters, such as tillage depth and tillage speed. Experiments were conducted to determine the effect of one of these operation parameters, tillage depth, on two widely used types of tillage implements: chisel- type and disc-type. The results showed that chisel-type implements are not heavily dependent upon tillage depth and retain much greater amounts of crop residue on the soil surface. Disc-type implements, however, bury larger amounts of crop residues and are much more likely to bury greater amounts if they are operating at deeper depths. Producers should be able to use the results of this research to select tillage implements and the depth at which they operate that will be more likely to leave large amounts of residue on the soil surface and prevent soil erosion.

Technical Abstract:
The ability of a tillage implement to maintain surface residue coverage is largely dependent upon its main active component. Two categories of tillage implements were compared to determine their ability to maintain large amounts of surface residue coverage when operating at different tillage depths. Chisel-type implements were found to bury substantially lesser amounts of crop residue than disc-type implements. Disc-type implements were also found to be highly dependent upon tillage depth. A more thorough understanding of the ability of tillage implements to maintain adequate amounts of surface residue coverage should enable producers to select appropriate implements to maximize production while minimizing erosion.